[计] anticipated carry adder, look-ahead carry adder

xiān xíng jìn wèi jiā fǎ qì ㄒㄧㄢ ㄒㄧㄥˊ ㄐㄧㄣˋ ㄨㄟˋ ㄐㄧㄚ ㄈㄚˇ ㄑㄧˋ